An e-cabinet key that is strong so it can open large doors with a lot of pressure from the waterproof seals. If you want a strong key make sure that there are at least 4 vertical perimeters in your slicer. 

The hole of the key is 6mm. The outer cylinder has a diameter of 9mm.

I do not recommend printing this model in PLA due to high torsional forces when the key is used.